A PA28 CFI MADE A DEAD STICK LNDG AT ZZZ AFTER HIS STUDENT INADVERTENTLY PLACED THE FUEL SELECTOR TO 'OFF' DURING A TRAINING FLT IN ZZZ AIRSPACE.

Narrative

WHILE ON A FIRST XCOUNTRY TRAINING FLT; THE STUDENT PLT SWITCHED THE FUEL SELECTOR FROM THE R TANK POS (FURTHEST FORWARD OR DOWN POS) THROUGH THE L TANK POS (CTR OR STRAIGHT UP POS) TO THE OFF POS. ENG WAS AT IDLE (1700 RPM); PROP WAS TURNING; AND ENG INSTS WERE NORMAL. I DECLARED AN EMER SIT WITH PARTIAL PWR AND WAS CLRED TO LAND AT ZZZ. I MADE A SUCCESSFUL LNDG ON RWY 7. NO DAMAGE OR INJURIES. AFTER LNDG I ATTEMPTED A RESTART WITHOUT SUCCESS. WHEN MY STUDENT MOVED HER SEAT BACK; I NOTICED THE FUEL SELECTOR IN THE OFF POS. I DID NOT RECOGNIZE THE PROB AS FUEL STARVATION SINCE THE ENG INSTS WERE ALL IN GREEN AND THE ENG WAS DEVELOPING 1800 RPM. I INITIALLY TURNED ON THE ELECTRIC FUEL PUMP (BACK UP) AND ATTEMPTED A RESTART. FROM THAT POINT ON; I CONCENTRATED ON SETTING UP BEST GLIDE SPD AND FLYING TO THE CLOSEST ARPT (ZZZ) AND MAKING A DEAD STICK LNDG. OTHER FACTORS CONTRIBUTING: NOT RECOGNIZING THAT THE FUEL WAS INADVERTENTLY TURNED OFF. I HAVE FLOWN OVER 40 HRS WITH THIS STUDENT AND EACH FLT REQUIRED THAT THE TANKS BE SWITCHED FROM R TO L (I ALWAYS START ON THE R TANK). I AM UNABLE TO SEE THE SWITCH FROM MY POS. THE ENG DID NOT FAIL ABRUPTLY.